1. Field of the Invention
This invention relates to buildings made of hollow “logs,” typically formed of metal and often referred to as metalogs, and more particularly to a novel, inexpensive and highly effective foundation for such buildings. It relates also to a novel method of laying the foundation.
2. Description of the Prior Art
Log buildings have a long history, as indicated in applicant's co-pending U.S. patent applications Ser. Nos. 12/157,051, 12/218,913 and 12/287,832, filed respectively on June 6, July 18 and Oct. 14, 2008. Those applications and the applicant's prior U.S. Pat. Nos. 4,619,089 and 5,282,343, issued respectively on Oct. 28, 1986, and Feb. 1, 1994, are incorporated herein by reference.
Traditional log buildings made of wood have drawbacks, including the sheer weight and bulk of the logs and the consequent expense and difficulty of shipping and handling them; their lack of uniformity, even when trimmed to size; the inevitable waste, and, in many locales, the scarcity of wood. Because of these drawbacks, wooden structures today are usually not made of logs but are framed with sills, joists, studs, rafters, and ridgepoles and finished with interior and exterior sheathing.
The '089 and '343 patents identified above and corresponding patents in other countries disclose the best examples in the prior art of metalog construction. Buildings following their teachings have been erected in many parts of the world and are finding wide and growing acceptance. Government authorities and private builders in various countries have endorsed them for good reasons, including the following:                they are suitable for residential and non-residential building construction;        they do not burn and are resistant to damage by termites;        galvanized steel or other metal or plastic material for forming the logs can be delivered to the building site as flat sheets and coils, with important savings in shipping costs;        using compact machinery that can be moved from site to site, unskilled labor can form the strip material into lightweight hollow “logs” and cut them to the required length at the site with no waste;        unskilled labor can easily position the logs by hand and use preformed end connectors to connect the logs in precise alignment;        the hollow logs, because of the enclosed air chambers and the thinness of the material, have (even if made of a heat-conducting material such as steel) inherent insulating properties; and        the time required for construction, from beginning to end, is but a fraction of the time required by traditional building methods, thereby making new construction quickly available on demand and reducing financing costs.        
Before erecting any building, including one made of metal logs, it is usually necessary to prepare the ground. This involves clearing and possibly grading or excavating an area, and then pouring a concrete basement or slab foundation upon which to erect the superstructure. A concrete basement or slab, even for a relatively small structure, requires bringing to the site cement, adequate sand, water, iron rods and electro-welded mesh, as well as a skilled mason. None of this is too complicated in urban and sub-urban construction sites, but in some remote areas, pouring a concrete slab can represent a real problem in terms of logistics.
Financial constraints are another impediment to the construction of buildings in certain areas of countries with emerging economies. It is often necessary to construct buildings at bare minimum cost; saving the cost of a concrete foundation may make it possible to build much-needed, permanent building superstructures that could not otherwise be afforded.